Booster



' Feb. 25,- 1936. M. A. GARRISON 2,031,828

BOOSTER Filed Dec. 10, 1952 s Sheets-Sheet 1 J]! J28 J45 J2 J38 INVENZ'OR: MZzrzbn'Amas 6 01715070,

I ATTORNEYS.

1936 M. A. GARRISON 2,031,828

' BOOSTER Filed Dec. 10, 1952 s Sheets-Sheet 2 INENTOR. Zia/ion Am Garrlls'am ATTORNEYS.

Feb. 25, 1936.

M. A. GARRISON BOOSTER Filed Dec. 10, 1932 3 Sheets-She et 3 'IIIIIIIIIII INVENT OR: Mal-27m Ames 'zu'rason,

ATTORNEY Patented "Feb. 25, 1936 STATES PATENT OFFICE steering elements of a motor vehicle, the steering of said vehicle is directly controlled by an operator thereof during any turning movement of the wheels of a vehicle, the present invention acting to assist in said turning, to the end that physical fatigue of the operator is prevented. In this respect, the device is applicable to all types of vehicles, such as heavy trucks and the like.

A further object is the provision of means of the character stated which assists in moving some means during simultaneous movement of a control device normally used for moving said means.

With respect to the foregoing object, it is elementary that in a vehicle, some hand control, such as a steering wheel, is utilized, together with suitable connections between said steering wheel and the turnable wheels of the vehicle. As the steering wheel is turned, the vehicle wheels are normally moved in one direction or the other. This constitutes the manual operation. I provide with my invention, a device directly controllable by movement of the steering wheel and associated with the steering mechanism for moving the vehicle wheels whereby turning of the steering wheel will cause my invention to operate in step with said turning, so that the normal effort used to turn the wheels is reduced to any degree desired, and my invention consists in the novel and useful provision of means for accomplishing this desired function.

Another object is the provision of means which is fool-proof in construction, and in the case of the adaptation of the invention for steering purposes, will not interfere with the regular steering even though a portion of the mechanism of this invention should fail to operate or be broken.

Another object is the provision of a device of the character stated, consisting of few parts which are readily assembled in position of service without the necessity of changing, to any appreciable degree, mechanism with which it is to be associated.

Other objects consist in the novel and useful provision of I a valve adapted to function in an eflicient and fool-proof manner in carrying out the functions of the invention.

other objects include a device which is simple of construction, inexpensive in cost of manufacture, requires few parts, is not easily broken, readily adaptable for various uses and purposes, and capable of producing efilcient results.

With the above and other object in view, the 5 invention consists in the novel and useful provision, formation, construction, association, and relative arrangement of'parts, members and features, all as shown in certain embodiments in the accompanying drawings, described generally, and 1 more particularly. pointed out in the claims.

In the drawings:

Figure 1 is a fragmentary top plan view of a vehicle incorporating the invention,

Figure 2 is an enlarged sectional view, partly 15 broken away, and taken substantially on the line 2-2 of Figure 1,

Figure 3 is a plan view of the mechanism shown in Figure 2,

.Figure 4 is a fragmentary view on the line 4-4 20 ofFigure 2,

Figure 5 is a sectional view on the line 5-4 of Figure 2,

Figure 6 is an enlarged view, partly in fragment, and on the line 6-6 of Figure 2,'and,

Figure 7 is a view on the line 1-1 of Figure 2.

Referring now with particularity to the drawings, in Figure l I have shown fra'gmentarily the frame I of a motor vehicle provided with dirigible wheels 2 and 3 adapted to be con-Jointly moved, 30,

normally, when a steering wheel 4 is rotated, which steering wheel, through the medium of the usual worm and sector or equivalent means 5 actuates a steering arm thrust rod 6 to in turn move a knuckle arm I, this knuckle arm being adapted 35 to directly cause movement of the wheel 3 and through the medium of steering knuckles 8 and 9 and a drag link or tie rod I ll, actuate the wheel 2. The parts just mentioned are, of course, well known in the art. 40

My invention is adapted to operate in conjunction with the steering mechanism and particularly that portion included between the worm and sector 5 and the thrust rod 6. I maylocate my invention in other positions, depending upon use of the invention, but for the present I am simply describing my invention in one environment, to-wit, to assist in the steering operation of a vehicle. With the environment stated in view, 50 I have provided means ll adapted to be fluid actuated to in turn cause movement of the thrust rod 6, together with means 12 controlling the admisson of a fluid to the said means ll under direct control of the steering mechanism before recited, and which fluid is maintained under pressure within suitable limits by a pump l3.

The pump I3 is conventional in form and, in the present instance, is of the rotary type and adapted to circulate a fluid or at least to maintain a pressure in the line, the details of said pump not being shown as no particular type of pump is contemplated. This said pump, assuming it to be the rotary type, may be secured by means of a bracket, to a portion of an engine I4 carried by the motor vehicle, the said pump being driven by a continuous belt l5 passed over a pulley l6 of the pump and a pulley I! carried by the crank shaft.

In the present embodiment of the invention, I prefer to circulate an oil and in this connection, I provide a tank l8 adapted to hold a body of oil and which tank is secured through the medium of a bracket or the like to the motor block M, as shown at I 9. The usual filler plug 20 is provided for the tank. The tank has an inlet and an outlet, as shown at 2! and 22, and a suitable tube connection 23 leads from the outlet of said tank to the intake opening 24 of the pump.

The remaining tube connections between the pump and the tank and the association thereof with the means l2 will be set forth later. At the present timeycertain of the connections that exist between the worm and sector and the thrust rod 6 will be described.

Referring to Figures 4 and 6, I preferably use in conjunction with my invention an irreversible type of steering gear. This steering gear incorporates what is known as a worm wheel shaft 25, and this worm wheel shaft has a squared portion. What I term the primary steering arm 28 is provided with a boss 21 having a squared opening 7 adapted to receive thesquared-portion of the shaft 25, as see Figure 6. The usual form of clamp 28 is adapted to secure the boss in tight engagement with the square. The said has 21 is: provided with an extension 29 substantially presenting a. circular periphery and with a portion 39 of reduced diameter and likewise screw-threaded, as shown at 3|. A secondary steering arm 32 is provided with a boss 33 formed with a through bore 34 through which the extension 29 is passed. A nut 35 is secured to the threads 3| for maintaining the boss 33 in position upon the extension 29. It will be seen that whereas the primary steering arm 26 is positively moved through the worm and gear arrangement 5, that the secondary arm 32 is not of necessity positively moved. Usually, the primary steering arm 26 is directly connected to the thrust rod 6. In the present instance, the thrust rod 6 is actuated by the secondary steering arm 32, the secondary steering arm to this end carrying a ball 36 received within a socket 31 on one end of the thrust rod 6. In order that movement should occur in the secondary arm when the primary arm is manually moved, I provide the primary steering arm with a yoke or bifurcated member 38, the furcations 39 and 49 of which spacedly straddle opposite side edges of the secondary arm 32. In order to cause movement of the secondary arm 32 when the arm 26 is positively moved, I provide members 4i and 42. These members are identical in construction and are carried by the furcations of the yoke. One of said members will be described. The furcation l0, 'as is likewise the furcation 39, is provided with a transverse threaded bore 43. A reducer type nut 44 is provided with external screw-threads 45 adapted for threaded engagement with the threads in the bore 43 of the yoke. This nut is further reduced as to diameter at 46 and is formed with two central bores of difierent diameters, as shown at 41 and 8. A flanged nut 49 is provided with a central screwthreaded bore 50. A pin or stem 5| having a portion of reduced diameter at 52 ispassed through the bores of the member 44, being 5 shouldered within the portion of reduced diameter of said member, with an end of said pin projecting beyond the inner surface of the furcation 40. The periphery of said pin adjacent its opposite end is provided with threads 53, which threads engage the threads 50 of the nut 49. A look nut is shown for the assemblage at 54, 'Interposed between the nuts 48 and .49 and particularly between the fiange portions thereof is a coil spring 55. The peripheries of the members 84 and 49 1 are threaded, as shown at 56 and 51, and a portion of the coils of said springs adjacent both ends thereof is adapted for engagement with the said threads 56 and 51. Compression of the spring between the members 44 and 49 is, to a certain degree, regulated by adjusting the nut 49 upon the threads 53. It will be seen that the spring may be put under tension by pushing against the end 59 of the stem 5|. The spring will be held to resist movement of the stem by its threaded engagement with the members 44 and 49. When the spring is secured to the threads of the said members l4 and 49, the original threading occurs in a direction tending to uncoil the spring. However,

if there is any tendency for the spring to release 69 of the pin 59 engage opposite sides of the 'secondary steering arm. Thus, when the primary steering arm is moved, the secondary steering arm which is floating upon the boss 33, will likewise be moved under spring tension. For instance, viewing Figure 2, the ends 53 and 60 of the pins engage sides of the secondary steering arm and are prevented from further movement thereagainst by the shouldering of the pins within the portions of reduced diameter of the members 44. Hence, it the primary steering arm is rotated clockwise, viewing Figure 2, the spring of the member "will be placed in tension for the reason that the yoke 39 which carries the said members 6! and i2, is fixedly carried by the primary, steering arm; hence, pressure will be exerted against one side of the secondary steering arm by the pin 5|. If great. resistance to movement of the secondary steering arm should occur, the spring of the member 82 wil be placed in considerable tension; however, the pin 59, particularly the end 69, will not follow movement of the secondary steering arm due to the shouldered relationship that exists between the said pin and the member 64.

It is to be remembered that the yoke. 18 fixedly carried by the primary steering. arm and thereiore the movement of said arm is directly; communicated to the secondary steering arm through the medium of the members M and 42. The secondary steering arm is not subject to any direct stress, and for. that reason will not under ordinary circumstances fail to move in step with the primary arm. However, sudden movementof the primary steering arm causes a lag in movement of the secondary steering arm due to inertia of moving parts, and the like, and the moend carries an arm H which is substantially at right angles to the longitudinal plane of said steering lever and likewise at an angle to the side face 62 of the lever 26. Said arm 6i is provided with a forked extremity 63.

The secondary arm 32 is provided adjacent the boss portion with an outstanding bracket 64 terminating in a boss 65 and likewise provided adjacent the opposite end of said arm 32 with a bracket 66 terminating in a boss 61. The brackets 4 60 and 66 are in alignment.

Extending between the said bosses 65 and 61 and projecting beyond the boss 65 is a shaft 68. Carried on the shaft and adjacent to and above the boss 61. is a collar 69 which is held to rotate with said shaft by suitable means, such as shown at 10, comprising a lock screw. Any other means might be utilized for locking the collar 69 to the shaft. The said collar is provided with a radial stud 1| adapted to be received between the forks of the forked end 63 of the arm 6|. This stud isprovided with curved sides and resembles the tooth of a pinion, as see Figure 3. The uppermost end of the said shaft 68 has secured thereto and above the boss 65 a hub 12 of a lever 13, by means of a set screw or the like 10. The lever 13 is provided at 15 with a stud 16 having a ball head 11. The center of .the ball head substantially centers with the longitudinal axis of the boss 21, extension 29, and the screwthreaded reduced portion 30.

A bracket 18 is secured to the vehicle framing and particularly the side framing member 19, and this said bracket pivotally carries a bell crank 90.

One arm 8| of said bell crank is provided with an elongated split socket 02 adapted to slidably receive therein the ball head 11. The opposite lever 93 of the said bell crank is associated with valve apparatus, as will hereinafter appear.

Adapted to be secured to the framing 19 is a casting including a pair of spaced brackets and 85, which brackets are provided with journal portions 86. Received between the said brackets is a cylinder 81 constituting a portion of the means II. This cylinder is provided with a pair of diametrically arranged trunnions 68 and 89', adapted to be received in the journal portions of the brackets, whereby the said cylinder may be rocked. The said cylinder is provided at one end with a closure cap 09 and the opposite end with a cap 90 provided with a stuffing box 9I. A piston 92 -is within the cylinder and the piston stem 93 is passed through the stufling box and carries exterior the cylinder a yoke 90. This yoke is adapted to be pivotally secured to an extension formed, on the secondary lever arm 32 and adjacent the outermost extremity thereof. This construction permits the cylinder to rock as the piston moves within the said cylinder responsive to rocking movement of the secondary lever arm. The bracket 95 has two portions at substantially right angles, towit, the portion that carries the journal and the portion at 96. This portion 96 acts as a supporting top for a valve that controls admissidn of fluid under pressure to the cylinder and, in this connection, the portion 96 is enlarged at 91 and provided with a pair of ports 96 and 99. These ports, in each instance, enter at one end of the said enlargement and are curved upwardly so as to have an opening in the top surface of said member 96, as best illustrated in Figure 2. Suitable connectors I00 and IOI are screw-threadedly received within the ports 98and 99 and suitable connectors I02 and I03 are screw-threaded in transverse openings adjacent ends of said cylinder 91, as shown in Figures 2 and 5. Flexible tubes I04 and I05 extend between the connectors I00 and I02, and IOI and I03. The periphery of the head of the piston is provided with circumferential right-triangled grooves I06. This grooved arrangement has been found to operate efllciently in the present invention. Any number of grooves may be provided, although in the present instance, there are two grooves facing one direction relative to the piston head and two grooves facing the opposite direction, so far as the hypotenuse portions of said grooves are concerned.

Carried on the top surface of the part 96 of the casting and secured thereto by any suitable means, such-as shown at I01, is the means I2, whichcontrols admission of fluid under pressure to the cylinder. The means I2'includes a housing I09 provided with a longitudinal bore I09, and a pair of spaced manifold members H0 and III. The interior of said housing I09 is provided with annular grooves II 2 to H1, inclusive. These annular grooves function as ports. A transverse opening II8 permits communication between'the interior-of the manifold H0 and the annular groove II 2, and a transverse bore I I9 permits communication between said manifold and the groove H5. The housing is likewise transversely bored at I20 and I2I, and which bores respectively communicate with the ports 98 and 99. The manifold H0 is known as the inlet and the manifold II I as the outlet. The manifold III communicates with the annular grooves H3 and H1.

Closely confined within the bore I09 is a sleeve or cage I22. One end of said sleeve or cage abuts against an end cap I23 held by means I24 to one end of the said housing I08. The opposite end of said housing is closed by a cap I25 provided with a stuiiing box 126. This said cage or sleeve is provided with transverse spaced bores, annularly arranged and adapted to communicate with the annular grooves in the housing, as

shown at I21 to I32, inclusive. The transverse bores are not all of the same diameter. For instance, the transverse bores I29, I30 and I 3I are of smaller diameterv than the transverse bores previously enumerated. The said sleeve or cage is likewise provided with small groups of annularly related transverse bores designated for the entire group as I33 and I3, the group I33 communicating with the annular groove I I4 and the group I3! with the annular groove II 6. Adapted for movement within the said sleeve or cage are valves I35, I36 and I31. The valve I35 is of the sleeve type, in that it comprises a tubular member, the periphery of which is fitted fairly tightly within the bore I09 of the housing I08, and which member is provided with a pinrality of annularly arranged transverse bores I39 adapted to register in' the position shown in Figure 2 with the transverse bores I21. This sleeve is provided at one end with a spider I39, this construction permitting openings I40 between arms of the spider. The other valve members I36 and I31 are conventional in form, being in the nature of a piston head and all of the said valve members are secured together for joint movement through the medium of a stem I4 I the said stem being passed through the stumng box I25. The stem is screw-threaded at I42, and a secondary stem l43'is coupled-with the stem I through the medium of a turnbuckle I44. The stem. I43 carries a yoke I45, this yoke being pivoted at I46 to the arm 83 of the bell crank 80. Suitable fittings I41 and I40 are provided for the manifolds H0 and III, and a flexible tube I49 communicates with a fitting I41 and with the outlet of the pump I 3.v A tube I50 is secured ,to the fitting I40 and communicates with the inle 2| of the tank 58.

The operation, uses and advantages of the invention are as follows:

When the engine I4 is in operation, the pump I3 is being actuated to in turn cause flow of fluid through the connections therewith leading to the intake manifold past certain elements of the valves, out the exhaust manifold into the reserve tank l8, and in turn from the outlet of said reserve tank to the intake of the pump. Assuming the motor vehicle is standing still with the engine running, fluid under pump pressure will enter the intake manifold I I0 through the transverse opening II8 into the annular port II2 of the housing I00, thence communicating with the transverse ports I21 through the ports I38 to the interior of the sleeve I35. The fluid will flow in turn through the longitudinal ports I40 into the space included between the spider end I39 of said sleeve valve and the cap I25. The fluid would likewise pass through the transverse-ports I28 of the sleeve into the annular port H3 of the housing. The outlet manifold Us in communication with the port I I3. Therefore, the arrangement so far provides for flow within the intake manifold through the by-pass parts which would include the ports H2, H0, I21, thence into the discharge ports H3 and I20. This is viewing the position of the valve in Figures 2 and 7. Fluid under pressure would likewise be directed by the intake manifold into the ports I I5, 9 and I30 into the space included between the two valves I36 and I31, thence through the ports I29 and I3I of the sleeve, which ports communicate with the ports 90 and 99 which, through suitable connections, lead to ends of the cylinder 81 and on opposite sides of the piston 92. It will be seen that the fluid under pressure is directed substantially equally in two directions so that the fluid pressure on both sides of the piston and within the cylinder is the same. The fluid used may be oil, although within the purview of the invention, I do not wish to necessarily confine myself to an incompressible fluid.

In future description, I will use the terms liquid and oil in place of the term fluid, as :it renders. the description of the operation in a certain measure easier to follow.

when the stem MI is moved, the three valves are'simultaneously moved, as previously set forth. It is also to be recalled that the sleeve is provided with a plurality of angularly arranged ports I33 and I34. If the vehicle is running upon the road and the operator thereof should desire to turn to the right, say a gradual turn, the steering wheel 4 would, of course, be turned to the right the proper degree. The irreversible worm and sector arrangement 5 would tend to rotate the worm wheel shaft 25 anti-clockwise, viewing the shaft in Figure 2. This movement of the shaft will likewise produce a swinging movement of the primary steering arm to the right, viewing Figure 2. The primary steering arm carries the bifurcated member 38. Movement of this bifur= catedmember will, through the medium of the I resiliently actuated pin 59 by its engagement with tionship relative to the secondary arm, thereby causing movement of the valve. The valve then exhausts liquid from one side of the piston, while admitting liquid to the other side; Thus, the piston moves with the primary and secondary arms, exerting force on the latter and continues to do so until it reeestablishes the central or a neutral relationship between the primary and secondary arms, thus restoring the valve to its neutral position. Movement of the secondary steering arm to the right will move the piston 92 within the cylinder in the direction of the closure cap 89. The thrust rod 6 is associated with the secondary steering arm through the ball and socket arrangement 36 and 31, as see Figure 4, and therefore the thrust rod will be moved when allow more oil to enter the cylinder to the left of: the piston. Thus, the oil would be returned through the connection I05, through the port 99 into the space included'between the valves I 36 and I31. However, if steering should be diflicult or the primary steering arm is rocked or moved suddenly to the right, the shaft 60 is rotated clockwise due to the fact that the secondary arm does not immediately followmovement of the primary arm. It is to be remembered that the primary steering arm carries the extended arm 6I provided with a bifurcated end 63, between the bifurcations of which end is received the stud 1I carried by the collar 69, which is fastened to the shaft 68; further,-that this shaft 68 is supported by brackets 64 and 66 secured to the secondary Figure 2, it will be noted that this ball head substantiaily lies in the longitudinal axis of the shaft 25. Hence, when the primary and secondary steering arms are rotated, the ball will remain in its longitudinal axis, and no ofi-center "elationship will occur tending to cause binding .1 the parts of the apparatus. However, as the shaft is rotated, the ball head will tend to follow a given are away from the longitudinal axis of the shaft 25 (see plan view of Figure 3), wherein it will be seen that while the ball is in the position shown in Figure 2 yet movement of the shaft will cause the ball to move in an are relative to the longitudinal axis of the shaft 25. However, this movement is slight and in actual practice, will never cause any binding of the parts, as previously stated. The arm 8i of the bell crank 80 is formed with a split socket 02 for receiving the ball. Hence, as the lever 13 moves clockwise, the

' through said ports.

bell arm 8I will be rotated anti-clockwise, to in turn rock the lever 83 to the left, viewing Figure 3. This movement to the left will likewise cause movement of the stem members I and I13 through the medium of the turn-buckle I to the left and as the stem I49 is directly associated withthe valves I35, I36 and I31, these valves will be moved to the left a given amount. Oil

then enters the intake manifold, through the bypass ports which include the ports I I2 to II8 and I21, through the sleeve valve ports I38 within the sleeve and out through the discharge ports I28 and H3 into the manifold I I I. After the sleeve valve has moved to the left, viewing Figure 2, the ports I38 of said valve now overlap the ports I2l of the sleeve and tend to restrict passage of oil At the same time, 011 is passing through the inlet ports H5, H9 and I39 to the space included between the two valves I36 and I31 but inasmuch as these valves have likewise moved to the left in step with movement of the sleeve valve I35, moreoil is being passed through the port 98 behind the piston 92 for the reason that the ports I33,are being opened and the ports I3I are being closed or lapped. The escape of liquid forward of the piston 92 through the port 99 is, therefore, regulated on the exhaust side of the valve arrangement. If movement becomes extensive enough, the ports I38 of the sleeve valve I35 will completely be closed, the ports I21 being lapped, at which time the ports I33 and I29 will be open and certain of the ports I34 progressively opened during said movement so that the oil is by-passed to the right of the valve I31 through the ports I" and I32 into the outlet manifold III. At this time, it is apparent that any liquid included between the cap I25 and the sleeve valve will be by-passed through the ports M9 and any oil, if confined in this space, is permitted to flow through the ports I I3 and I28, called the discharge ports, into the outlet manifold II I. It is perhaps unnecessary to state that the oil would be conducted through the flexible connection I59 from the outlet manifold, back to the housing or reserve tank II 8, thence to the pump where the oil is recirculated into the intake manifold III). 8

If an opposite turning movement is desired, it is apparent that opposite movement of the valves and likewise of the piston would occur. Thus, if a turning movement of the wheels to the left was desired, the valves would move to the right of the showing of Figure 2 and the piston 92 to the left. The ports I28, I30 and I32 are never overlapped by the valves. These ports are known as the discharge, inlet, and discharge, respectively. The by-pass set of ports are overlapped during certain movement of the sleeve valve I35, to the end that more oil is directed through the inlet ports to cause increased pressure on one or the other side of the piston 92, depending upon the turning direction desired for the wheels of the vehicle. The ports in the valve sleeve leading to the cylinder at opposite ends thereof are adapted to be progressively opened or closed, depending upon movement of two valve members and, as previously stated, the relationship is such that movement of the piston 92 within its cylinder is controlled by regulating the outlet or escape of the liquid in front of the piston. It has been found that this gives more positive action and better control of the device.

The springs or resilient members adapted to maintain the pins against sides of the secondary steering arm are of great importance and has been previously described. However, if excess pressure is required to turn the wheels to the right, as given in the previous example, the primary or fixed steering arm would tend to tension the spring of the member 4| due to contact between the pin 59, and the secondary or floating arm. The pin 5| would not follow movement of the secondary steering arm, due to the shouldered arrangement that exists between said pin and the nut 4|. This inward movement of the pin would, of course, turn theshaft G8 to a greater degree than it would ordinarily be turned if the primary and secondary steering arms had slight relative movement due to slight resistance to turning action. Therefore, under sudden requirement and excess load, the sleeve valve and the other two valves would be moved to their extreme positions where the by-pass port would be completely overlapped by the sleeve valve. However, when the pressure necessary for sudden turning is no longer required, the secondary steering arm would tend to again be restored to the position in alignment with the primary steering arm and the spring of the member ll would no longer be in tension. When this happens, there will be a movement of the valves tending to allow a portion of the oil received in the intake manifold to by-pass into the exhaust manifold. There is, of course, a gradual lessening of oil pressure back of the piston 92.

To further elucidate, the re-establishment of the central or neutral relationship between the primary and secondary arms takes place when the driver has turned his steering wheel the desired amount, and either holds it in that position, or allows it to reverse its rotation to the position it takes when driving substantially straight ahead. In the event the steering wheel is held stationary after turning it, and the effort required to make the turn caused relative movement between. the steering and primary arms (thus moving the valve from its central or neutral position), the piston will continue to be moved by the fluid pressure until it has restored the valve to the neutral or central position. The piston 92 in its movement restores the valve to its neutral position by moving the steering arm 32 through connections .83, 94, and 95, to a central position with respect to the furcations 39 and 40 on primary arm 29. Simultaneously, shaft 88 is rotated to the center of its arc of movement by means of the engagement of stud II with the forked end 63 of the arm 6|, which is integral with the primary arm 26. Since the lever I3 is rigidly fastened to shaft 68, restoring shaft 68 to the center of its arc of movement also restores the .bell crank 80 to the center of its arc of movement through the connection of the elongated split socket 82 on the end of arm 8|, and the ball head 11 on lever I3. The opposite lever 83 .of the said bell crank thus pulls or pushes on the valve by means of the connections I ll to I43, inclusive, thereby restoring the valve to its central or neutral position. The exception taken care of.

to this condition occurs when more eifort is required to hold the front wheels in the desired position while rounding a turn than is exerted by one or the other of the springs. In this case, the valve is by-passing the flow from the pump, but has been moved slightly from its central position, and is so restricting the flow through the by-pass as to cause' a fluid pressure against the piston exactly suflicient to hold the valve in the desired position. When the steering wheel is reversed to the straight ahead position after completing a turn, the valve may or may not be in its neutral position, depending on conditions. If the vehicle is traveling ,at a suflicient rate of speed to allow the normal castor action of the front wheels to restore them to the straight ahead position without assistance, the springs exertsuificient effort-to hold the steering and'primary arms in neutral or central relationship.

without relative movement, and both arms move as one with the steering gear "shaft? When-the;

The inclined or angular setofi'smallport 3,5 and I34 allows'ra soft-gentle actionofgthepiston'.

92 during movement thereof compensated springs of -the members; 4| (or 42.'--" Wl fSSure in the system'isgreater'movementof theslide valves :-to' admit-:morex'liquid under pressure hehind the spistom jdependingi on the direction of turning, movementof the; wheels. In the case of high pressures in the lines due to driving the vehicleat a'high speed, a slight movement of the steering wheel will produce sufficient pressure to aid in 'thesteerlng byf-slight opening of the valve. In any event, the elongation of one or the other of the springs of the members 4| or 42. will determine the travel of the valves under conditions encountered by the driver.

If the booster system should fail to function, it is apparent that the steering of the vehicle is not affected in the least because the yoke or bifurcated member 38 carried by the primary steering arm closely surrounds the secondary steering arm. Therefore, leaks in the system, breakage of springs of one of the members 4! or 42, loss of the cylinder, or the like, would not in any way impair the mechanical steering of the vehicle.

I claim:

1. In a device of the character disclosed, a manually turnable shaft, two arms carried thereon, one of said arms being fixed to the shaft and the other of said arms floating thereon, said fixed arm provided with a yoke having two spaced apart legs and said floating arm being between said-legaresilient abutments between said legs of the yoke and the floating arm; each resilient abutment having a pin for push engagement with the floating arm, and a coil spring adapted to be tensioned when a pin is moved in one direction.

2. In a device of the character disclosed, a manually turnable shaft, two arms carried thereon, one of said arms being fixed to the shaft and the other of said arms floating thereon, said fixed arm provided with a yoke having two spaced apart legs and said floating arm being between said legs, resilient abutments between said legs ofthe yoke and the floating arm; each resilient abutment having a pin for push engagement with the floating arm, a coil spring adapted to be tensioned when a pin is moved in one direction, the opposite pin of the resilient abutment remaining stationary, and means for adjusting the position of said pins relative to the floating arm.

3. In a device of the character disclosed, a manually movable shaft, a pair 01 levers carried thereon, one of said levers being flxed'to said shaft and the other of said levers floating on the shaft, 2, pair of arms provided with bearings spacedly secured to the floating lever, a shaft carried by the bearings of said arms, a collar provided with a'tooth secured to said shaft, an anncarried by the fixed lever and extending at an angle relative thereto and provided with a bifurcated head adapted to recei ge said tooth; movement of the; fixed arm relative to the float- ;ing arm rotating js'a'idrshaftgmmn movement bebifurca dhea'd and tooth.

the'character disclosed, a

manually 'movabler shaft, apair of levers carried hereonfone pr? said levers being fixed to said haft; and the other "of said levers floating on theshaft, a pair of arms provided with bearings 'spacedl'y secured to the floating lever, a shaft carried bythe bearings of said arms, a collar provided with a tooth secured to said shaft, an

' arm carried by the fixed lever and extending at an angle relative v thereto and provided with a bifurcated head adapted to' receive said tooth;

movement of the fixed arm relative to the floating arm rotating said shaft upon movement between said bifurcated head and tooth, an arm carried byone end of said shaft, a bell crank arm, means of connection between said bell crank arm and said arm carried by the shaft, whereby turning of the shaft turns the bell. crank arm, and said means of connection being in alignment with the central axis of the manually movable shaft, in combination with fluid actuated means controlled as to movement by said bell crank lever.

5. In a device of the character disclosed, a manually movable shaft, a pair of levers carried thereon, one of said levers being fixed to said shaft'and the other of said levers floating on the shaft, a pair of arms provided with bearings spacedly secured to the floating lever, a shaft carried by the bearings of said arms, a collar provided with a tooth secured to said shaft, an arm carried by the fixed lever and extending at an angle relative thereto and provided with a bifurcated head adapted to receive said tooth; movement of the fixed arm relative to the floating arm rotating said shaft upon movement between said bifurcated head and tooth, an arm carried by one end of said shaft, a bell crank arm, means of connection between said bell crank arm and said arm carried by the shaft, whereby turning of the shaft turns the bell crank arm, said means of connection being in alignment with the central axis of the manually movable shaft, a valve to be actuated by movement of the bell crank arm, and said means of connection between the bell crank arm and arm carried by the shaft due to its central position relative to the axis of the manually movable shaft and the levers carried thereby providing uniform valve travel.

6. In a device of the character disclosed, a manually turnable shaft, a pair of levers mounted on said shaft and normally in parallel alignment, the shaft acting as an axis therefor, one

of said levers being fixed to the shaft-and the other of said levers being oscillatable relative to the shaft and said fixed lever; a second shaft oscfllatable in step with movement of the oscillatable lever, means between the fixed lever and said second shaft for rotating said second shaft when said levers are shifted from substantially parallel alignment a valve to be moved, and means between the valve and the shaft carried by the oscillatable arm operable from a central point with respect to the axis of said manually movable shaft and the two levers carried thereby to cause uniform valve travel.

'7. A device of the character disclosed, a valve including a housing provided with intake and outlet manifolds, a sleeve within said housing, both said sleeve and said housing provided with ports, a sleeve valve and a pair of spaced pistontype valves interconnected for like movement within said sleeve, said sleeve valve being formed with a port, two of said ports in said sleeve and housing communicating with the intake manifold and with the port of the sleeve .valve and with the space included between the two piston valves, said sleeve and housing provided with a pair of spaced ports communicating with opposite sides of the two piston valves and with the outlet manifold, a cylinder having a piston therein to be moved by fluid under pressure, separate means of communication for ends of said cylinder and with spaced ports in said sleeve and housing of the valve and normally communicating with the space included between the two piston valves when the said valves are in a -neutral position, a source for delivering fluid under pressure to said intake manifold and said fluid under pressure when said piston valves are in a neutral position, being passed through the ports in the valve housing and sleeve equally within the cylinder for centralizing the piston and likewise through the port in said sleeve into the ports communicating with the outlet manifold.

8. A device of the character disclosed, a valve including a housing provided with intake and outlet manifolds, said housing provided with ports, a sleeve valve and a pair of spaced pistontype valves interconnected for like movement within said housing, said sleeve valve being formed with a port, two of said ports in said housing communicating with the intake manifold and with the port of the sleeve. valve and with the space included between the two piston valves, said housing provided with a pair of spaced ports communicating with opposite sides of the two piston valves and with the outlet manifold, a cylinder having a piston therein to be moved by fluid under pressure, separate means of communicaports in said housing of the valve and normally communicating with the space included between the two piston valves when the said valves are in a, neutral position, a source for delivering fluid under pressure to said intake manifold and said fluid under pressure when said piston valves are in a neutral position, being passed through the ports in the valve housing equally within the cylinder for centralizing the piston and likewise through the port in said sleeve into the ports communicating with the outlet manifold, said piston valves and said housing both provided with ports of restricted area whereby when all of said pistons are moved in one direction, one set of ports of the said piston valve opens, the other of said ports decreasing inarea and in such a manner that the piston to be moved within the cylinder is controlled as to movement by the passage of fluid from one side of said cylinder.

9. A device of the character disclosed, a valve including a housing provided with intake and outlet manifolds, said housing provided with ports, a sleeve valve and a pair of spaced pistontype valves interconnected for like movement within said housing, said sleeve valve being formed with a port, two of said ports in said housing communicating with the intake manifold and withthe port of the sleevevalve and with the space included between the two piston valves, said housing provided with a pair of spaced ports communicating with opposite sides of the two piston valves and with the outlet manifold, a cylinder having a piston therein to be moved by fluid under pressure, separate means of communication for ends of said cylinder and with spaced ports in said housing of the valve and normally communicating with the space included between the two piston valves when the said valves are in a neutral position, a source for delivering fluid under pressure to said intake manifold and said fluid under pressure when said piston valves are in a neutral position, being passed through the ports in the valve housing equally within the cylinder for centralizing the piston and likewise through the port in said sleeve into the ports communicating with the outlet manifold, movement of the valves being simultaneous and in such a manner that fluid directed under pressure within the intake manifold through the sleeve valve to both sides of the piston valves leading to the outlet manifold may be gradually restricted as to passage, the fluid under pressure between the two piston valves being increased as to pressure. p

' MARION AMES GARRISON. 

